1. Field of the Invention
The present invention relates to a disk braking device in which a disk plate fixed to a wheel is interposed by friction members, and a motorcycle provided with the disk braking device.
2. Description of Related Art
In some disk braking devices for motorcycles there are a multiplicity of “lightening” holes formed at circumferential intervals on the disk plate in order to decrease the weight of the disk plate. In addition, recesses are sometimes formed at circumferential intervals at an outer edge of the disk plate in order to suppress brake noise (see, for example, WO 2004/042247).
In such disk plates, the lightening holes are typically arranged in a radially aligned and parallel configuration, and a heat insulation portion is formed in a radial direction. This leads to impaired disk plate heat radiation quality and makes the friction members more liable to wear.